Indian Space Research Organisation (ISRO's) Mars Orbiter, which is currently at a distance of 60 lakh kilometers from Earth, has so far burnt about 55 per cent of the 850 kilograms of fuel it is carrying.

"We have already spent 470 kilogram of the bio-propellant we are carrying. However, we have not overspent,despite the glitch that we encountered during the fourth burn (while circling the earth. We are well within the nominal limit of spending," said AS Kiran Kumar, a senior scientist working on the Mars Orbiter Mission (MOM) and the director of city-based Space Application Centre (SAC), an arm of ISRO.

Instead of the scheduled five burns, the orbiter had to conduct six earth burns before the Trans-Mars Injection phase.

"This is a mission where we are using the most minimal of energy possible. The next round of fuel will be burnt in the Trajectory Correction Maneuvers (TCM) that will be undertaken in the months of April and August 2014. About 200 kg of fuel will be burnt in a matter of 28 minutes on September 24, 2014, during the Mars Orbit Injection phase," said Kiran Kumar while talking about the mission on the sidelines of a talk on ISRO's Mars Mission organised at Ahmedabad Management Association on Wednesday evening.

The first TCM was carried out on December 11.

The senior ISRO scientist said that indigenously developed Ceramic Servo Accelerometer (CSA) that measures the precise amount of velocity the satellite gains when the thrusters are burnt have "enabled in preserving the fuel on-board." This CSA on the MOM is an improved version of the one deployed during the Chandrayaan Mission.

"About 190 kgs of fuel was spent on Tran-Mars Injection phase on December 1 which was perhaps the toughest part of the mission so far," said Kiran Kumar while addressing an audience at AMA.

The Mars orbiter which was launched on November 5 is at a distance of 60 lakh kilometers from Earth and is currently travelling at a speed of 3.4 kilometer per second through space. By the time the orbiter reaches Mars, it will attain a velocity of 34 kilometer per second.

"We are currently communicating with the satellite using the on-board medium gain antenna. Any message sent to it currently takes 12 seconds to reach. This gap will keep on increasing till the furthest point when a signal sent from Earth will take 20 minutes to travel one-way," said Kiran Kumar.